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path: root/drivers/spi/spi-rspi.c
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2014-08-16spi: rspi: Configure DMA slave bus width to 8 bitGeert Uytterhoeven
The new Renesas R-Car Gen2 DMA Controller driver (rcar-dmac) requires explicit configuration of the DMA slave bus width. Hardcode the DMA transfer size to 1 byte for both directions, as that's the only supported configuration (16-bit DMA support was removed in commit 9c5de2c1754c2bb3c69c4d7bf0d0edc0a61d8232 ("spi: rspi: Remove unused 16-bit DMA support")). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-08-16spi: rspi: Use devm_kasprintf()Geert Uytterhoeven
Use the devm_kasprintf() helper function instead of open coding error-prone buffer handling and string formatting. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-08-16spi: rspi: Remove unneeded semicolonGeert Uytterhoeven
Introduced by commit 426ef76dd8a394a0e04d096941cd9acb49539a3e ("spi: rspi: Add DT support"). Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-08-16spi: rspi: Fix leaking of unused DMA descriptorsGeert Uytterhoeven
If dmaengine_prep_slave_sg() or dmaengine_submit() fail, we may leak unused DMA descriptors. As per Documentation/dmaengine.txt, once a DMA descriptor has been obtained, it must be submitted. Hence: - First prepare and submit all DMA descriptors, - Prepare the SPI controller for DMA, - Start DMA by calling dma_async_issue_pending(), - Make sure to call dmaengine_terminate_all() on all descriptors that haven't completed. Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-07-16spi: rspi: Handle dmaengine_prep_slave_sg() failures gracefullyGeert Uytterhoeven
As typically a shmobile SoC has less DMA channels than devices that can use DMA, we may want to prioritize access to the DMA channels in the future. This means that dmaengine_prep_slave_sg() may start failing arbitrarily. Handle dmaengine_prep_slave_sg() failures gracefully by falling back to PIO. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-07-07spi: rspi: Pass spi_master pointer to rspi_release_dma()Geert Uytterhoeven
rspi_release_dma() doesn't need access to any fields in the driver private data, except for the pointer to the SPI master object. Hence just pass the needed pointer. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-07-07spi: rspi: Remove unused variable in rspi_rz_transfer_one()Geert Uytterhoeven
Introduced by commit 8b983e90ea1a3dd82070f96c062ad521a06b7cc0 ("spi: rspi: Extract rspi_common_transfer()"), which removed its users. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Extract rspi_common_transfer()Geert Uytterhoeven
Extract the common parts of rspi_transfer_one(), rspi_rz_transfer_one(), and qspi_transfer_out_in() into the new function rspi_common_transfer(). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Add DMA support for RSPI on RZ/A1HGeert Uytterhoeven
Enable DMA support for RSPI on r7s72100 (RZ/A1H). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Add DMA support for QSPI on R-Car Gen2Geert Uytterhoeven
Enable DMA support for QSPI on R-Car Gen2, for Single, Dual, and Quad SPI Transfers. Performance figures for reading from a QSPI FLASH driven at 24.375 MHz on r8a7791/koelsch: - Single: 1.1 Mbps PIO, 23 Mbps DMA - Dual : 12.7 Mbps PIO, 48 Mbps DMA - Quad : 13 Mbps PIO, 70 Mbps DMA Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Absorb rspi_rz_transfer_out_in() into rspi_rz_transfer_one()Geert Uytterhoeven
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Merge rspi_*_dma() into rspi_dma_transfer()Geert Uytterhoeven
rspi_send_dma() and rspi_send_receive_dma() are very similar. Consolidate into a single function rspi_dma_transfer(), and add missing checks for dmaengine_submit() failures. Both sg_table pointer parameters can be NULL, as RSPI supports TX-only mode, and unidirectional DMA transfers will also be needed later for Dual/Quad DMA support. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Pass sg_tables instead of spi_tranfer to rspi_*_dma()Geert Uytterhoeven
The DMA routines only need access to the scatter-gather tables inside the spi_transfer structures, hence just pass those. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Move RSPI-specific setup out of DMA routinesGeert Uytterhoeven
Refactor RSPI (on SH) DMA handling to make it reusable for other RSPI implementations: - Call the DMA routines after configuring the TX Mode bit and after calling rspi_receive_init(), so these RSPI-specific operations can be removed from the DMA routines, - Absorb rspi_transfer_out_in() into rspi_transfer_one(). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Use SPI core DMA mapping frameworkGeert Uytterhoeven
Use the SPI core DMA mapping framework instead of our own. If available, DMA is used for transfers larger than the FIFO size (8 or 32 bytes). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: SPI DMA core needs both RX and TX DMA to functionGeert Uytterhoeven
The SPI DMA core framework needs both RX and TX DMA to function. As a preparation for converting the driver to use this framework, fall back to PIO if no DMA channel or only one DMA channel is available. This affects only RSPI, which could do DMA transfers for TX-only before. RSPI-RZ and QSPI (at least for Single SPI Transfers) will need both RX and TX DMA anyway. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Remove unneeded resource test in DMA setupGeert Uytterhoeven
The resource is know to exist, as rspi_probe() already mapped it. Remove the test, and just pass the resource. Pass the device pointer instead of the platform device pointer, as the latter is no longer needed. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Extract rspi_request_dma_chan()Geert Uytterhoeven
Setup of the receive and transmit DMA channels is very similar, so let's consolidate. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Don't consider DMA configuration failures fatalGeert Uytterhoeven
Fall back to PIO if DMA configuration failed. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Extract rspi_pio_transfer()Geert Uytterhoeven
The various PIO loops are very similar. Consolidate into a single function rspi_pio_transfer(). Both buffer pointers can be NULL, as RSPI supports TX-only mode, and Dual/Quad SPI Transfers are unidirectional. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Use core SPI_MASTER_MUST_[RT]X handlingGeert Uytterhoeven
RSPI needs dummy transfers to generate the SPI clock on receive. RSPI-RZ and QSPI always do both transmit and receive. Use the SPI core SPI_MASTER_MUST_RX/SPI_MASTER_MUST_TX infrastructure instead of checking for the presence of buffers and providing dummy data ourselves (for PIO), or providing a dummy buffer (for DMA). rspi_receive_dma() now provides full duplex DMA transfers on RSPI, and is renamed to rspi_send_receive_dma(). As the SPI core will always provide a TX buffer, the logic to choose between DMA send and DMA send/receive in rspi_transfer_one() now has to check for the presence of an RX buffer. Likewise for the DMA availability tests in rspi_is_dma(). The buffer tests in qspi_transfer_one() are now always true, so they're removed. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Remove unused 16-bit DMA supportGeert Uytterhoeven
The 16-bit DMA support doesn't fit well within the SPI core DMA framework, as it needs to manage its own double-sized temporary buffers, for handling the interleaved data. Remove it, as there is no in-tree board code that sets rspi_plat_data.dma_width_16bit. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Do not call rspi_receive_init() for TX-onlyGeert Uytterhoeven
Since commit 8449fd76deb9ac67a15a6fb8ead7bb4595d019d2 ("spi: rspi: Merge rspi_send_pio() and rspi_receive_pio()"), rspi_receive_init() is called for transmit-only transfers too, while this is not needed. Only call rspi_receive_init() when receiving, to preserve behavior on RSPI on SH. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02spi: rspi: Extract rspi_wait_for_{tx_empty,rx_full}()Geert Uytterhoeven
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-05-26spi: rspi: Round up division to avoid slave overclockingGeert Uytterhoeven
The calculation of the bit rate divider used a standard C division, which rounds down the quotient. This may lead to a higher bitrate than requested. Round up to avoid this. E.g. on Koelsch, the SPI flash (configured for 30 MHz) was driven at 48.75 MHz. After this patch it's driven at a safe 24.375 MHz. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-03-11spi: rspi: Add runtime PM support, using spi core auto_runtime_pmGeert Uytterhoeven
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-23spi: rspi: Fix loopback mode for Dual/Quad SPI TransfersGeert Uytterhoeven
While normal Dual and Quad SPI Transfers are unidirectional, we must do a bidirectional transfer if loopback mode is enabled, else rx_buf is not filled. With spidev it seemed to work, as spidev uses the same buffer for tranmission and reception. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-23spi: rspi: Remove empty rspi_cleanup()Geert Uytterhoeven
If spi_master.cleanup() is not needed, it can be left unimplemented. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-04spi: rspi: Only enable interrupts when there's a need to waitGeert Uytterhoeven
rspi_wait_for_interrupt() unconditionally enables interrupts, even when the wait condition is already satisfied. This causes a high interrupt load (2 interrupts/byte for full-duplex Single SPI transfers, 1 interrupt/byte for RSPI with TX Only mode, or QSPI in unidirectional Dual or Quad Transfer mode). Change this to return immediately when the wait condition is satisfied. This dramatically reduces the interrupt load, especially in high-speed Quad Transfer mode, and increases transfer speed, as no interrupts need to be handled when there's space available in the output FIFO, or data available in the input FIFO. Benchmark results for QSPI on r8a7791 while reading 1 MiB from 30 MHz SPI FLASH on the Koelsch development board: Before: Single SPI Dual SPI Quad SPI Interrupts: 2096856 1048592 1048594 Mbps: 0.9 1.6 1.6 After: Single SPI Dual SPI Quad SPI Interrupts: 1048569 21295 8 Mbps: 0.7 10.8 12.9 I don't know why Single SPI slowed down a bit. I've also verified functionality for RSPI-RZ on r7s72100, but don't have benchmark results as there's no SPI FLASH connected to RSPI on the Genmai development board. Unlike RSPI and QSPI, RSPI-RZ has separate interrupts for RX and TX, which shows that Single SPI transfers now generate (mostly) RX interrupts, as expected. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-03spi: rspi: fix build error when CONFIG_OF is not setShimoda, Yoshihiro
This patch fixes an issue that the following build error happens when the CONFIG_OF is not set: drivers/spi/spi-rspi.c: In function 'rspi_probe': drivers/spi/spi-rspi.c:1203:26: error: 'rspi_of_match' undeclared (first use in this function) Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-30spi: rspi: Add support for Quad and Dual SPI Transfers on QSPIGeert Uytterhoeven
Add support for Quad and Dual SPI Transfers on the Renesas Quad Serial Peripheral Interface, as found in R-Car Gen2 SoCs like R-Car H2 (r8a7790) and R-Car M2 (r8a7791): - Add unidirectional transfer methods for Quad/Dual SPI Transfers. - Program the sequencer to handle SPI messages with multiple transfer modes when Quad or Dual transfers are enabled for an SPI slave. Up to 4 transfer modes per SPI message are supported by the hardware. - Advertise the availability of Quad and Dual SPI modes on QSPI. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-29spi: rspi: Add DT supportGeert Uytterhoeven
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27spi: rspi: Use NULL as the clock IDGeert Uytterhoeven
There's only one RSPI/QSPI clock, so we can use NULL as the clock ID Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27spi: rspi: Convert to clk_prepare_enable/disable_unprepareGeert Uytterhoeven
Get the driver ready for the migration to the common clock framework by calling clk_prepare_enable() and clk_disable_unprepare(). Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27spi: rspi: Add support for loopback modeGeert Uytterhoeven
Add support for specifying loopback mode. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27spi: rspi: Add support for RSPI on RZ/A1HGeert Uytterhoeven
Add support for the RSPI variant in the RZ/A1H (r7s72100) SoC. Main differences with RSPI on SH are: - Lack of TX only mode, hence we always have to use full duplex transfers, - The Data Register must be accessed used 8-bit operations. RSPI on RZ is matched using the new "rspi-rz" platform device name. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27spi: rspi: Add support for more than one interruptGeert Uytterhoeven
Add support for multiple interrupts, based on the SDK reference code. This is needed for RZ/A1H, which supports 3 interrupts. When using multiple interrupts, they must be called "rx" (SPRI) and "tx" (SPTI). The error interrupt (SPEI) is not used, as it matters for slave mode only. When using a single interrupt, it may be called "mux". If it cannot be found, the first interrupt in the device's resources will be used. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27spi: rspi: Merge qspi_send_pio() and qspi_receive_pio()Geert Uytterhoeven
qspi_send_pio() and qspi_receive_pio() are very similar: they both send and receive full duplex data to/from the hardware, but ignore the data stream in the unused direction. Merge them into qspi_transfer_out_in(), now supporting real full duplex. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27spi: rspi: Merge rspi_send_pio() and rspi_receive_pio()Geert Uytterhoeven
rspi_send_pio() and rspi_receive_pio() are very similar: - the former only sends data, using TX Only Mode, - the latter sends and receives full duplex data to/from the hardware, but uses dummy transmit data. Merge them into rspi_transfer_out_in(), now supporting full duplex if needed. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27spi: rspi: Abstract transfer_one() for RSPI and QSPIGeert Uytterhoeven
Split off qspi_transfer_one() (which doesn't support DMA yet) from rspi_transfer_one(). Replace the abstraction of send_pio()/receive_pio() by the abstracrion of transfer_one(). Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27spi: rspi: Add rspi_data_{out,in,out_in}() helpersGeert Uytterhoeven
Add helpers rspi_data_{out,in,out_in}() to write, read, or write and read data to/from the Data Register, taking care of waiting until data or space is available in the buffers. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27spi: rspi: Abstract 8/16-bit Data Register accessGeert Uytterhoeven
Add rspi_{write,read}_data(), to abstract 8-bit (QSPI, and RSPI on RZ/A1H) versus 16-bit (RSPI) Data Register access. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27spi: rspi: Use core message handlingGeert Uytterhoeven
Let the generic SPI core handle SPI messages, calling into our rspi_transfer_one() method. rspi_assert_ssl() and rspi_negate_ssl() are absorbed into rspi_prepare_message() and rspi_unprepare_message(), as they actually enable/disable the whole SPI function, instead of just (de)asserting the chip select line. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-27spi: rspi: Remove unused mesg parameter from {send,receive}_pio()Geert Uytterhoeven
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-23Merge commit 'spi/fix/rcar' into spi-linusMark Brown
2014-01-17spi: Remove duplicate code to set default bits_per_word settingAxel Lin
The implementation in spi_setup() already set spi->bits_per_word = 8 when spi->bits_per_word is 0 before calling spi->master->setup. So we don't need to do it again in setup() callback. Signed-off-by: Axel Lin <axel.lin@ingics.com> Acked-by: Marek Vasut <marex@denx.de> Acked-by: Barry Song <Baohua.Song@csr.com> Acked-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-14spi: rspi: Add missing clk_disable() calls in error and cleanup pathsGeert Uytterhoeven
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-14Merge branch 'topic/rcar' of ↵Mark Brown
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-rspi
2014-01-14spi: rspi: Spelling s/transmition/transmission/Geert Uytterhoeven
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-01-13spi: rspi: Add support for specifying CPHA/CPOLGeert Uytterhoeven
Add support for specifying the SPI clock phase and polarity, based on the SDK reference code. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mark Brown <broonie@linaro.org>
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